Laser lights danced Wednesday across the yawning cavern of Siemens Energy's $350 million expansion, an imposing display of health in the Charlotte energy and manufacturing sectors.

Siemens will build and refurbish gas turbines for U.S. and worldwide customers in the 450,000-square-foot addition, which adjoins an existing, 700-worker steam turbine and generator plant. Siemens has hired another 700 workers since announcing the expansion early last year and expects to bring in 400 more by 2014.

Gov. Bev Perdue, who helped court Siemens, called the expansion a step toward rebuilding North Carolina's manufacturing base after textiles and furniture shrank.

"We want to be identified as a state that builds things," she said.

Siemens will receive $21.7 million in state incentives if it achieves job-creation, investment and wage goals.

The massive investment comes as economic turmoil roils much of the world, including Siemens' base in Germany, slowing demand for the electricity its components make. But company officials see a light at the end of that tunnel, and it comes in the form of natural gas.

Siemens says gas will be the fuel to replace the United States' fleet of aging coal-fired power plants. Natural gas burns more cleanly than coal and more easily passes environmental standards. Gas turbines start quickly, making them potentially ideal companions to smooth the fluctuating output of solar and wind farms.

And gas is plentiful in the United States. Rapid expansion of a technique to blast gas out of shale rock, hydraulic fracturing, and horizontal drilling have increased shale-gas production by 48 percent a year since 2006, the Energy Information Administration says.

"It's really going to be the solution of choice," said Mark Pringle, operations director for Siemens in Charlotte. "Our customers are getting more and more excited about the availability of natural gas at a competitive level."

Thirteen months after groundbreaking in October 2010, the site of a former employee parking lot now holds a massive structure with cranes capable of lifting 450 tons. The new plant is certified LEED Gold, a standard of environmentally friendly buildings.

Following remarks Wednesday by Perdue and company officials, curtains opened to reveal the first gas turbine to leave the new plant. The turbine, built for the copper-mining company Grupo Mexico, will power a 250-megawatt plant that Siemens will build in Sonora State, Mexico. Siemens will also build a second turbine for Grupo.

With the expansion, Siemens expects its Charlotte site to increase exports to $400 million a year. Its 1,400 employees make it second-largest, to Duke Energy, among the 250 energy companies in the Charlotte region. More than 110,000 people work in manufacturing in the region, the Charlotte Chamber of Commerce says.

Siemens has partnered with UNC Charlotte and Central Piedmont Community College to train engineers and machinists to operate its precise, computer-controlled manufacturing equipment. About 450 of the 700 new hires are professional positions, such as engineers, earning $60,000 to $80,000 a year, Pringle said.

Companywide, Siemens employs 60,000 U.S. workers and says its components generate one-third of the nation's electricity.